Prior art circuit breakers conventionally utilize both main and arcing contact tips carried by the movable and stationary contact assemblies, with the arcing contact tips, and arrangements for causing the arcing contact tips to separate after separation of the main contact tips, adding to the manufacturing and maintenance costs.
Prior art power circuit breakers create a magnetic repulsion force between the movable and stationary contact assemblies due to current flow therethrough in opposite directions. While some magnetic repulsion is desirable, as it aids in quick separation of the movable and stationary contacts when the circuit breaker is tripped under load, short circuit currents can provide magnetic forces having magnitudes sufficiently great to damage mechanical components of the contact assemblies.
Prior art power circuit breakers conventionally pivot one or more main contact fingers of the stationary contact assembly, with load and short circuit currents being required to flow through the pivotable joint. Currents of high magnitude can cause the pivotable parts to weld, destroying necessary functions of the main contact fingers of the stationary contact assembly.
Thus, it would be desirable, and it is an object of the present invention, to eliminate arcing contact tips in a power circuit breaker, and thus the costly arrangements for causing arcing contact tips to separate after main contact tips have separated. It would also be desirable, and it is another object of the invention, to reduce the magnitude of the magnetic forces which operate upon the stationary contact assembly, to reduce the chance of damaging components thereof during heavy current flow. It would also be desirable, and it is another object of the invention, to reduce the magnitude of the current flow through pivotable joints of independent contact fingers of the stationary contact assembly, to reduce the chance of overheating and welding occurring in these joints.